Use of Rubber Dams During Root Canal Treatment in Taiwan

Background/PurposeIsolation of teeth with rubber dams is an important procedure for infection control in dentistry, especially in endodontic treatment. This study surveyed the prevalence of rubber dam usage in nonsurgical root canal treatment (RCT) by dentists under the National Health Insurance system in Taiwan.MethodsA total of 1,332 completed RCT cases were randomly selected from a large database from the Bureau of National Health Insurance in Taiwan in 2004. The radiographs and dental charts of the selected cases were evaluated for the prevalence of rubber dam usage in RCT. The frequencies of rubber dam usage for RCT by dentists were compared between hospitals and private dental clinics and among six different regions in Taiwan.ResultsThe overall prevalence of rubber dam usage for RCT by dentists under the National Health Insurance system in Taiwan was 16.5%. The frequency of rubber dam usage for RCT by dentists in hospitals (32.8%) was significantly higher than that (10.3%) in private dental clinics (p < 0.0001). However, there was no significant difference in the frequency of rubber dam usage for RCT by dentists among six different geographic regions in Taiwan.ConclusionThe prevalence of rubber dam usage for RCT by dentists in Taiwan is relatively low. Because rubber dam isolation of an endodontically-treated tooth can provide better infection control, increase patient protection, and improve treatment efficiency, there is an urgent need to advise dentists in Taiwan to use rubber dams for every RCT case

Zero-point entropies of spin-jam and spin-glass states in a frustrated magnet

Thermodynamics of glassy states in a quasi-two-dimensional frustrated magnet Ba$_2$Sn$_2$ZnCr$_{7p}$Ga$_{10-7p}$O$_{22}$ where $p$ is the spin density are investigated experimentally. The system features a triangular network of bipyramids of spins with the quantum spin number $s = 3/2$. The DC magnetic susceptibility measurements on a series of samples with $0.44 \le p \le 0.98$ show a freezing transition with the transition temperature $T_\mathrm{f} \le 1.2$ K. $T_\mathrm{f}$ is found to decrease with decreasing $p$. The low-lying excitations in the glassy state of the system are examined via the temperature dependence of the magnetic heat capacity and are shown to consist of two components: the hydrodynamic Halperin-Saslow modes characteristic of a spin jam and the two-level systems of a spin glass. A continuous crossover between the two glassy states is observed via the varying weights of the two components as the spin density is varied. The $p$ dependence of the spin jam's zero-point entropy determined from the exotic perimeter-scaling behavior combined with the observed zero-point entropy of the samples provides the $p$ dependence of the spin glass's zero-point entropy. The obtained result shows that the correlations between orphan spins begin below $p \sim 0.8$, the limit that was also found using a neutron scattering technique in a previous report on the isostructural compound SrCr$_{9p}$Ga$_{12-9p}$O$_{19}$. The domain size of the spin-jam state estimated from the value of the zero-point entropy for the cleanest sample is approximately $4 \times 4$ bipyramids, about 2.5 times the measured spin correlation length

YC-1 [3-(5Ј-Hydroxymethyl-2Ј-furyl)-1-benzyl Indazole] Inhibits Neointima Formation in Balloon-Injured Rat Carotid through Suppression of Expressions and Activities of Matrix Metalloproteinases 2 and 9

ABSTRACT Matrix metalloproteinases (MMPs), particularly MMP-2 and MMP-9, and postrevascularization production of vascular smooth muscle cells may play key roles in development of arterial restenosis. We investigated the inhibitory effect of 3-(5Ј-hydroxymethyl-2Ј-furyl)-1-benzyl indazole (YC-1), a benzyl indazole compound, on MMP-2 and MMP-9 activity in a ballooninjury rat carotid artery model. Injury was induced by inserting a balloon catheter through the common carotid artery; after 14 days, histopathological analysis using immunostaining and Western blotting revealed significant restenosis with neointimal formation that was associated with enhanced protein expression of MMP-2 and MMP-9. However, these effects were dosedependently reduced by orally administered YC-1 (1-10 mg/ kg). In addition, gelatin zymography demonstrated that increased MMP-2 and MMP-9 activity was diminished by YC-1 treatment. On the other hand, YC-1 inhibited hydrolysis of the fluorogenic quenching substrate Mca-Pro-Leu-Gly-Leu-DpaAla-Arg-NH 2 by recombinant MMP-2 and MMP-9 with IC 50 values ϭ 2.07 and 8.20 M, respectively. Reverse transcription-polymerase chain reaction analysis of MMP-2 and MMP-9 mRNA revealed that YC-1 significantly inhibited mRNA levels of MMPs. Finally, for the YC-1 treatment group, we did not observe elevation of cGMP levels using enzyme-linked immunosorbent assay, suggesting that YC-1 inhibition of neointimal formation is not through a cGMP-elevating pathway. These data show YC-1 suppression of neointimal formation is dependent on its influence on MMP-2 and MMP-9 protein, mRNA expression, and activity, but not through a cGMP-elevating effect. YC-1 shows therapeutic potential for treatment of restenosis after angioplasty. During the past 20 years, one focus of cardiovascular pharmaceutical research has been the development of drugs that inhibit intimal hyperplasia. Despite many attempts, no clinical trial has proven that there is an effective pharmacological solution to the problem Matrix metalloproteinases (MMPs) are a family of structurally related zinc-endopeptidases that degrade components of extracellular matrix associated with vascular remodeling during vascular injury-induced neointima formatio

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Is either anosmia or constipation associated with cognitive dysfunction in Parkinson's disease?

ObjectiveTo clarify the association of anosmia or constipation with cognitive dysfunction and disease severity in patients with Parkinson's disease (PD).MethodsNewly diagnosed patients with PD (less than 5 years) without a clinical diagnosis of dementia were included from February 2017 to August 2018. The subjects were further divided into subgroups based on whether anosmia occurred and the grade of constipation. The severity of PD motor symptoms was rated using the Movement Disorder Society-Sponsored Revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS), and cognitive functions were evaluated by Montreal Cognitive Assessment (MoCA). Statistical analyses including t-tests, chi-square tests, multiple linear regression, and binary logistic regression were used to determine statistical significance.ResultsA total of 107 newly diagnosed PD patients were included in this study. The MoCA score was significantly lower in the anosmia group (p ConclusionsAnosmia but not constipation was associated with cognitive impairment in PD patients. Nevertheless, severe constipation was associated with impaired olfaction and PD disease severity. We suggest that the propagation of α-synuclein from the olfactory route is distinct from the enteric nervous system, but the intercommunication between these two routes is complex

Échelles de longueur caractéristiques des réacteurs électrochimiques à plasma pour la synthèse de nanomatériaux

International audienceMany approaches to nanomaterials synthesis can require high temperature, strong/toxic reducing agents, or are complex/expensive. The plasma electrochemical reactor (PEC), composed of an atmospheric-pressure plasma with an aqueous electrode, may provide unique physico-chemical conditions that overcome these difficulties because non-equilibrium electrochemistry and nucleation are initiated in solution without additional heating or reducing agents. Indeed, the synthesis of graphene quantum dots (GQD) has been successfully demonstrated by PEC [1,2].We seek to develop a detailed mechanism of GQD growth, which likely involves complex non-equilibrium plasma chemistry and interactions near the plasma-liquid interface. Up to now, the chemistry of the liquid phase has mainly been inferred from ex situ or volume-averaged measurements. Conventional experimental techniques suffer from a lack of selectivity and/or degradation of dyes, chemical probes, or spin traps/probes introduced into the liquid. Spatial resolution is often poor or inaccessible.To move beyond ex situ techniques, we have developed an in situ multi-diagnostics approach to encompass a wide range of physical and chemical properties at the plasma-water interface. In particular, this platform features in situ spontaneous Raman microspectroscopy, which is advantageous because of its non-intrusiveness, selectivity, versatility, and straightforward calibration. Using a light-sheet technique, we have probed the interfacial region with micron-scale spatial resolution. To gain insight into the effect of the plasma on the solvent, we tracked the Raman spectrum of water. In particular, from the shape of the –OH stretch band, we observe that the plasma weakens the hydrogen bonding network of water near the interface. Also, near the interface, the concentrations of aqueous H2O2 and NO3- both show an excess in concentration relative to the bulk liquid [3]. Similar interfacial layers have been modeled for radical species such as OH but not for long-lived species such as NO3-.Concerning GQDs, we tracked their production via in situ photoluminescence (PL) spectroscopy. The PL intensity reached a maximum at mm depth rather than near the interface. In addition, particle image velocimetry showed that the liquid flow field exhibits a low-velocity zone at this depth. Together, these results provide the fullest description to date of the reaction environment during GQD synthesis.AcknowledgmentsFinancial support: ANR grants ANR-15-CE06-0007-01 and ANR-11-LABX-0017-01, PHC Orchid 40938YL, CNRS-IEA “GRAFMET”.References[1] Orrière, T., Kurniawan, D., Chang, Y. C., Pai, D. Z., & Chiang, W. H. (2020). Nanotechnology 31 (485001).[2] Yang, J. S., Pai, D. Z., & Chiang, W. H. (2019). Carbon 153, 315-319.[3] Pai, D. Z. (2021) J. Phys. D. : Appl. Phys. 54, 35520

Échelles de longueur caractéristiques des réacteurs électrochimiques à plasma pour la synthèse de nanomatériaux

International audienceMany approaches to nanomaterials synthesis can require high temperature, strong/toxic reducing agents, or are complex/expensive. The plasma electrochemical reactor (PEC), composed of an atmospheric-pressure plasma with an aqueous electrode, may provide unique physico-chemical conditions that overcome these difficulties because non-equilibrium electrochemistry and nucleation are initiated in solution without additional heating or reducing agents. Indeed, the synthesis of graphene quantum dots (GQD) has been successfully demonstrated by PEC [1,2].We seek to develop a detailed mechanism of GQD growth, which likely involves complex non-equilibrium plasma chemistry and interactions near the plasma-liquid interface. Up to now, the chemistry of the liquid phase has mainly been inferred from ex situ or volume-averaged measurements. Conventional experimental techniques suffer from a lack of selectivity and/or degradation of dyes, chemical probes, or spin traps/probes introduced into the liquid. Spatial resolution is often poor or inaccessible.To move beyond ex situ techniques, we have developed an in situ multi-diagnostics approach to encompass a wide range of physical and chemical properties at the plasma-water interface. In particular, this platform features in situ spontaneous Raman microspectroscopy, which is advantageous because of its non-intrusiveness, selectivity, versatility, and straightforward calibration. Using a light-sheet technique, we have probed the interfacial region with micron-scale spatial resolution. To gain insight into the effect of the plasma on the solvent, we tracked the Raman spectrum of water. In particular, from the shape of the –OH stretch band, we observe that the plasma weakens the hydrogen bonding network of water near the interface. Also, near the interface, the concentrations of aqueous H2O2 and NO3- both show an excess in concentration relative to the bulk liquid [3]. Similar interfacial layers have been modeled for radical species such as OH but not for long-lived species such as NO3-.Concerning GQDs, we tracked their production via in situ photoluminescence (PL) spectroscopy. The PL intensity reached a maximum at mm depth rather than near the interface. In addition, particle image velocimetry showed that the liquid flow field exhibits a low-velocity zone at this depth. Together, these results provide the fullest description to date of the reaction environment during GQD synthesis.AcknowledgmentsFinancial support: ANR grants ANR-15-CE06-0007-01 and ANR-11-LABX-0017-01, PHC Orchid 40938YL, CNRS-IEA “GRAFMET”.References[1] Orrière, T., Kurniawan, D., Chang, Y. C., Pai, D. Z., & Chiang, W. H. (2020). Nanotechnology 31 (485001).[2] Yang, J. S., Pai, D. Z., & Chiang, W. H. (2019). Carbon 153, 315-319.[3] Pai, D. Z. (2021) J. Phys. D. : Appl. Phys. 54, 35520

Échelles de longueur caractéristiques des réacteurs électrochimiques à plasma pour la synthèse de nanomatériaux

International audienceMany approaches to nanomaterials synthesis can require high temperature, strong/toxic reducing agents, or are complex/expensive. The plasma electrochemical reactor (PEC), composed of an atmospheric-pressure plasma with an aqueous electrode, may provide unique physico-chemical conditions that overcome these difficulties because non-equilibrium electrochemistry and nucleation are initiated in solution without additional heating or reducing agents. Indeed, the synthesis of graphene quantum dots (GQD) has been successfully demonstrated by PEC [1,2].We seek to develop a detailed mechanism of GQD growth, which likely involves complex non-equilibrium plasma chemistry and interactions near the plasma-liquid interface. Up to now, the chemistry of the liquid phase has mainly been inferred from ex situ or volume-averaged measurements. Conventional experimental techniques suffer from a lack of selectivity and/or degradation of dyes, chemical probes, or spin traps/probes introduced into the liquid. Spatial resolution is often poor or inaccessible.To move beyond ex situ techniques, we have developed an in situ multi-diagnostics approach to encompass a wide range of physical and chemical properties at the plasma-water interface. In particular, this platform features in situ spontaneous Raman microspectroscopy, which is advantageous because of its non-intrusiveness, selectivity, versatility, and straightforward calibration. Using a light-sheet technique, we have probed the interfacial region with micron-scale spatial resolution. To gain insight into the effect of the plasma on the solvent, we tracked the Raman spectrum of water. In particular, from the shape of the –OH stretch band, we observe that the plasma weakens the hydrogen bonding network of water near the interface. Also, near the interface, the concentrations of aqueous H2O2 and NO3- both show an excess in concentration relative to the bulk liquid [3]. Similar interfacial layers have been modeled for radical species such as OH but not for long-lived species such as NO3-.Concerning GQDs, we tracked their production via in situ photoluminescence (PL) spectroscopy. The PL intensity reached a maximum at mm depth rather than near the interface. In addition, particle image velocimetry showed that the liquid flow field exhibits a low-velocity zone at this depth. Together, these results provide the fullest description to date of the reaction environment during GQD synthesis.AcknowledgmentsFinancial support: ANR grants ANR-15-CE06-0007-01 and ANR-11-LABX-0017-01, PHC Orchid 40938YL, CNRS-IEA “GRAFMET”.References[1] Orrière, T., Kurniawan, D., Chang, Y. C., Pai, D. Z., & Chiang, W. H. (2020). Nanotechnology 31 (485001).[2] Yang, J. S., Pai, D. Z., & Chiang, W. H. (2019). Carbon 153, 315-319.[3] Pai, D. Z. (2021) J. Phys. D. : Appl. Phys. 54, 35520